System for detachably coupling an unmanned aerial vehicle within a launch tube

ABSTRACT

A system comprising an unmanned aerial vehicle launch tube comprising a sabot disposed in an interior of the launch tube, the sabot having a first clasp tab and an expandable skirt. The sabot is hollow, and the expandable skirt has a circumferential skirt protrusion and is configured to provide a pressure seal with the inner circumferential wall of the launch tube. The system further comprises a clasp detachably coupled to the first clasp tab and contacting the inner circumferential wall of the launch tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/US2013/044697, filed Jun. 7, 2013, which claims priority to andbenefit of Provisional Patent Application No. 61/656,949 filed Jun. 7,2012, both of which are hereby incorporated herein by reference in theirentirety for all purposes.

TECHNICAL FIELD

This invention relates to launch tubes that have a sabot; and moreparticularly to launch tubes and canisters, report-suppressing launchtubes, and sabots, for an unmanned aerial vehicle (UAV).

BACKGROUND

Typically UAVs are shipped to a launch site in an unassembled state. Atthe site they are assembled, tested, and launched. Launching istypically executed by hand, by an elastic tether, a powered wench, froma moving vehicle, or some combination thereof. Such methods can be timeconsuming and/or cumbersome. Once launched, a UAV may receive uplinksand may be guided by a human-in-the-loop, a human intermittentlyup-linking course corrections, e.g., via supervisory control, or by apreloaded intercept/strike point in combination with an onboard flightpath guidance generator and outputs of inertial sensors and/or from aGlobal Positioning System (GPS) receiver.

SUMMARY

An unmanned aerial vehicle (UAV) launch tube apparatus is disclosed thatmay include at least one layer of prepeg substrate disposed about anaperture to form a tube, a sabot disposed in an interior of the tube,the sabot having a first clasp tab, and a clasp detachably coupled tothe first clasp tab and contacting an inner circumferential wall of thetube so that the clasp is rotationally constrained by the innercircumferential wall and the first clasp tab. The sabot may alsocomprise an expandable skirt to provide a pressure seal with the innercircumferential wall of the tube. The expandable skirt may be axiallyrestrained within the tube using an adhesive, and the adhesive maydetachably bind the expandable skirt about a shell within the tube. Insuch an embodiment, the shell may consist of an exterior surface of agas generator, the gas generator configured to generate gas to generatea high-pressure volume between the expandable skirt and the shell, andwherein the generated pressure is sufficient to push the expandableskirt off of the shell by breaking the adhesive restraint between theexterior surface of the gas generator and the expandable skirt. Theapparatus may also have a UAV seated on the sabot, the UAV having asecond clasp tab detachably coupled to the clasp and wherein the claspis rotationally constrained by the inner circumferential wall, the firstclasp tab, and the second clasp tab. The sabot may be tethered to thetube. The sabot may include a base sabot configured to engage the UAV,the base sabot having a first plurality of expandable partial skirtseals, and a circumferential sabot skirt seated on the base sabot, thecircumferential sabot skirt having a second plurality of expandablepartial skirt seals, so that the first and second pluralities ofexpandable partial skirt seals complete the pressure seal with the innercircumferential wall. The expandable skirt may be axially restrainedwithin the tube using an adhesive, and the adhesive may detachably bindthe expandable skirt about a shell within the tube so that generation ofgas by the gas generator pushes the expandable skirt off of the gasgenerator by breaking the detachable binding of the adhesive. A UAV maybe seated on the sabot, the UAV having a second clasp tab detachablycoupled to the clasp, wherein the inner circumferential wall preventsthe clasp from slipping off of the second clasp tab while the UAV is inthe tube.

A method of launching an unmanned aerial vehicle (UAV) is disclosed thatincludes generating gas in a gas generator, introducing the gas to ahigh-pressure volume between an expandable sabot skirt of a sabot andthe gas generator to break an adhesive coupling that restrains the sabotin a launch tube, pushing the expandable sabot skirt against an innercircumferential wall of the launch tube using the gas, and driving thesabot up a launch tube using the gas. The method may also be definedwherein the adhesive coupling includes an adhesive coupling between theexpandable skirt and a shell surrounding the gas generator. The methodmay also include clasping a UAV to the sabot using a clasp, andrestraining the clasp against the inner circumferential wall of thelaunch tube to prevent the clasp from decoupling from at least one ofthe UAV and the sabot. In some embodiments, the method may also includesliding the clasp past the inner circumferential wall to release atleast one of the UAV and sabot from the clasp, and may include tetheringthe sabot to the launch tube to prevent the sabot from exiting thelaunch tube.

In another embodiment, a method of launching an unmanned aerial vehicle(UAV) includes restraining a sabot in a launch tube, introducing gas toa high-pressure side of an expandable sabot skirt of a sabot to breakthe restraint of the sabot in the launch tube, pushing the expandablesabot skirt against an inner circumferential wall of the launch tubeusing the gas, and driving the sabot up a launch tube using the gas. Insuch embodiments, the a sabot may be restrained using an adhesive, andthe adhesive may be used to restrain an expandable skirt of the sabot toa shell surrounding a gas generator in the launch tube. The method mayalso include tethering said sabot to said launch tube. The expandablesabot skirt may also include a circumferential skirt protrusion thatextends from said expandable sabot skirt toward an inner circumferentialwall of said launch tube. The method may also include restraining thetravel of said sabot by a tether configured to prevent said sabot fromexiting said launch tube, and where the restrained travel of said sabotsubstantially retains said gas within said launch tube. In someembodiments, the tether may be attached to said sabot and said innercircumferential wall of said launch tube by a tether reel and/or awinding element.

Another embodiment may include an unmanned aerial vehicle (UAV) launchtube apparatus, comprising: a first aperture portion, where said firstaperture portion comprises a constant cross-sectional area; a secondaperture portion, where said second aperture portion comprises anenlarged cross-sectional area relative to said first aperture portion,and where said first aperture portion and said second aperture portionform a launch tube; a sabot disposed in said first aperture portion andconfigured to detachably couple to a UAV; where said sabot is configuredto decouple from said UAV upon movement of said sabot from said firstaperture portion to said second aperture portion. The sabot may beconfigured to detachably couple to said UAV by a clasp, said claspconfigured to detachably couple to a first clasp tab of said sabot and asecond clasp tab of said UAV. Said clasp may be rotationally constrainedby at least one of: an inner surface of said first aperture portion,said first clasp tab of said sabot, and said second clasp tab of saidUAV. Said clasp may be configured to decouple from said second clasp tabof said UAV upon movement of said sabot from said first aperture portionto said second aperture portion. Said clasp may be configured todecouple from said first clasp tab of said sabot upon movement of saidclasp past an inner surface of said second aperture portion. Someembodiments may also comprise at least one gas generator, where said atleast one gas generator is disposed in a bottom portion of said firstaperture portion; and an expandable sabot skirt of said sabot, where ahollow end of said expandable sabot skirt is oriented toward said atleast one gas generator, and where said expandable sabot skirt isaxially restrained by a detachable restraint. Said at least one gasgenerator may be configured to generate gas, and said expandable sabotskirt may be configured to substantially retain said gas within saidlaunch tube. Said generated gas may be configured to detach saidexpandable sabot skirt from said detachable restraint and propel saidsabot from said first aperture portion to said second aperture portion.Said expandable sabot skirt may be configured to expand to said enlargedcross-sectional area of said second aperture portion and continue tosubstantially retain said gas in said second aperture portion of saidlaunch tube. Some embodiments may further comprise a tether attached tosaid sabot and a bottom portion of said first aperture portion, wheresaid tether may be configured to restrain a movement of said sabot suchthat said expandable sabot skirt substantially retains said gas fromescaping past an opening in said launch tube.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments are illustrated by way of example and not limitation in thefigures of the accompanying drawing, and in which:

FIG. 1 depicts one embodiment of an expandable skirt coupled to a shellwithin a launch tube using an adhesive, and the sabot detachably coupledto a UAV;

FIG. 2 is an expanded view of the expandable skirt, adhesive and shellfirst illustrated in FIG. 1 as gas pressure builds in a high-pressurevolume against the expandable skirt;

FIG. 3 is an expanded view of the expandable skirt, adhesive and shellfirst illustrated in FIG. 1 as the expandable skirt breaks an adhesivecoupling that restrains the sabot in the launch tube;

FIG. 4 depicts gas driving the sabot up the launch tube illustrate inFIG. 1, and the sabot detachably coupled to the UAV using a clasp thatis restrained by an inner sidewall of the launch tube;

FIGS. 5 and 6 depict an exemplary UAV launch tube with the sabotdetachably coupled to the UAV using, in one embodiment, a clasprestrained by the inner sidewall of the launch tube;

FIG. 7 depicts the clasp illustrated in FIGS. 5 and 6 falling away fromthe UAV as the inner sidewall restraint is removed;

FIGS. 8 and 9 depict an exemplary UAV launch with the sabot detachablycoupled to the UAV using, in one embodiment, a clasp restrained by theinner sidewall of the launch tube within one portion of the launch tube;

FIG. 10 depicts the clasp illustrated in FIGS. 8 and 9 falling away fromthe UAV as the inner sidewall restraint is removed in another portion ofthe launch tube;

FIGS. 11 and 12 depict a UAV launch tube with another embodiment of anenlarged-aperture launch end, with a UAV and sabot coupling clasprestrained by the inner sidewall of the launch tube within one portionof the launch tube; and

FIGS. 13 and 14 depict an exemplary UAV with its airfoils deployed andits pusher propeller rotating.

DETAILED DESCRIPTION

An unmanned aerial vehicle (UAV) launch tube apparatus is disclosed thathas prepeg substrate disposed about an aperture to form a tube, a sabotis disposed in the interior of the tube with the sabot having a firstclasp tab, and a clasp is detachably coupled to the first clasp tab andcontacts an inner circumferential wall of the tube so that the innercircumferential wall restrains the clasp from slipping off of the firstclasp tab while the UAV is in the tube. In this manner, the UAV may beassembled, tested and restrained in the launch tube prior to furthertransportation to a launch site.

FIG. 1 illustrates one embodiment of a UAV 108 that is detachablyrestrained in a launch tube 100 for testing and/or furthertransportation to a launch site. The launch tube 100 may have inner andouter circumferential walls (102, 104) disposed about an aperture 106.In some embodiments, the launch tube 100 may be formed of a singlewalled structure. The UAV 108 is illustrated disposed in the aperture106 adjacent the inner circumferential wall 102, with the UAV 108detachably coupled to a sabot 110 that is itself disposed in the launchtube 100. The sabot 110 may be hollow having an open end 112 orientedtoward a high-pressure volume 114. A tether 116 may attach to the sabot110, within a hollow of the sabot 110, and also attach to the inner wall102 of the launch tube 100.

The UAV 108 may have a radial indentation 118 at a proximal end 120 ofthe UAV 108 from which a UAV clasp tab 122 may extend radially towardthe inner circumferential wall 102 for coupling to a fastener 124.Similarly, the sabot 110 may have a clasp tab 126 extending radiallytoward the inner circumferential wall 102 from a radial indentation 128at a proximal end 130 of the sabot 110 for coupling to the fastener 124.As illustrated in FIG. 1, the UAV and sabot clasp tabs (122, 126) may berotationally aligned in complementary opposition to one another toenable the fastener 124, for example, a clasp 124 such as a u-shapedclasp, to detachably embrace both the UAV and sabot clasp tabs (122,126). For example, each of the UAV and sabot clasp tabs (122, 126) mayform a horizontal and planar surface, or substantially horizontal andsubstantially planar surface, upon which a complementary portion of theclasp 124 may rest when positioned to embrace the UAV and sabot clasptabs (122, 126). Once the UAV 108, sabot 110 and clasp 124 are insertedinto the launch tube 100, the inner circumferential wall 102 mayrotationally restrain the clasp 124 from falling off of both the UAVclasp tab 122 and sabot clasp tab 126 to accomplish a coupling betweenthe UAV 108 and sabot 110 that is detachable once the innercircumferential wall 102 no longer rotationally restrains the clasp 124.

In an alternative embodiment, the clasp 124 may be detachably coupled tothe UAV clasp tab 122, and rotatably coupled to the sabot 110 at a hinge(not shown). In such an embodiment, the clasp 124 may rotate about thehinge (not shown) as the rotational restraint of the clasp 124 by theinner circumferential wall 102 is removed by, for example, the UAV 108and clasp 124 beginning to exit the launch tube 100 or as the aperture106 diameter is suitably increased.

The sabot 110 may be formed with, or assembled with, an expandable skirt132 that may be axially restrained and detachably coupled to the innerwall 102 of the launch tube 100 downstream from a gas generator 134. Asillustrated in FIG. 1, the expandable skirt 132 may be detachablycoupled to a circumferential shell 136 within the tube using an adhesivecoupling 138 to establish the high-pressure volume 114 between theexpandable skirt 132 and circumferential shell 136. The circumferentialshell 136 may be defined by an exterior surface of the gas generator134. During operation, gas from the gas generator 134 may be introducedto the high-pressure volume 114. The resultant gas pressure pushes outon and expands the expandable skirt 132 at the adhesive coupling 138 tobreak the expandable skirt 132 free from the circumferential shell 136.The resulting gas pressure on the expandable skirt 132 may cause, or atleast facilitate, the formation of a gas seal between the sabot 110 andthe inner circumferential wall 102 of the launch tube 100 to betterdrive the sabot 110 along the inner wall 102 of the launch tube 100 byusing the gas pressure differential between the high-pressure volume 114and the side of the sabot opposite from the high-pressure volume.Formation of the pressure seal between the expandable skirt 132 and theinner circumferential wall 102 may be facilitated by a circumferentialskirt protrusion 140 that may be formed in, and extend from, theexpandable skirt 132 toward the inner circumferential wall 102 of thelaunch tube 100. In certain embodiments, the sabot 110 may be configuredto form gaps between the sabot 110 and the inner circumferential wall102 to provide a desired amount of gas leakage to prevent the launcherfrom becoming too hot or from containing the launch gases such that thestructural integrity of the launcher is compromised or breached.Accordingly, sabot 110 embodiments may be sized to limit gas leakageand/or to limit the sound propagation of the sonic waves generatedduring the UAV 108 launch process.

The inner circumferential wall 102 may be formed of a prepeg substratesuch as epoxy prepreg aramid fiber (KEVLAR®). The clasp 124 may be arigid member formed of a thermoplastic polymer such as polyvinylchloride (PVC), or formed of a metal such as aluminum or steel. Theclasp 124 may be rotationally restrained by the inner circumferentialwall 102 of the launch tube 100 against the UAV 108 and sabot 110.

FIG. 2 is an expanded view of the expandable skirt 132, adhesivecoupling 138, and shell 136, first illustrated in FIG. 1, as gaspressure builds in the high-pressure volume 114 against the expandableskirt 132. The expandable skirt 132 may be detachably coupled to theshell 136 using the adhesive coupling 138. In an alternative embodiment,the adhesive coupling 138 may be replaced with another coupling that isconfigured to break upon gas 200 reaching a predetermined gas pressurewithin the high-pressure volume 114, for example, a suitable pincoupling the expandable skirt 132 to the shell 136. The circumferentialskirt protrusion 140 may abut against the inner circumferential wall 102as gas 200 is introduced into the hollow of the sabot.

FIG. 3 is an expanded view of the expandable skirt 132 and shell 136,first illustrated in FIG. 1, where gas pressure in the high-pressurevolume presses against the expandable skirt to break an adhesivecoupling 138 that restrains the sabot in the launch tube 100. Uponreaching a predetermined pressure, the adhesive coupling 138 isinsufficient to couple the expandable skirt 132 to the shell 136 andadhesive restraint is broken between the exterior surface of the shell136 and the expandable skirt 132 to axially release the expandable skirt132 and sabot. The gas 200 continues to push the expandable skirt 132against the inner circumferential wall 102 of the launch tube toreinforce the gas seal to drive the sabot up the launch tube. Althoughthe expandable skirt 132 is illustrated as adhesively coupled to theshell 136 at a base 300 of the launch tube 100 and shell 136, theexpandable skirt 132 may be coupled to a position higher on the shell136. Also, although the adhesive coupling 138 is illustrated as having abead or spheroid shape, the adhesive coupling 138 may take the form of athin layer adhesive wherein the expandable skirt 132 may “rip” or peelaway from the adhesive coupling 138 in response to the gas 200 reachinga predetermined gas pressure in the high-pressure volume 114 to push theexpandable skirt 132 away from the shell 136.

FIG. 4 depicts the sabot 100, illustrated in FIG. 1, after release ofthe expandable skirt 132 from the shell 136 surrounding the gasgenerator 134. The gas generator 134 continues to generate gas 200 topressurize the high-pressure volume 114 resulting in differentialpressure against the expandable skirt 132 between the high-pressurevolume 114 and the remainder of the launch tube to reinforce the gasseal that may exist between the circumferential skirt protrusion 140 andthe inner circumferential wall 102. The sabot 110 may thus drive the UAV108 through the aperture 106 and up the launch tube 100. The tether 116coupled to the sabot 110 continues to spool outward to enable the sabot110 to continue up the launch tube 100. The UAV 108 may remaindetachably coupled to the sabot 110 through the clasp 124, with theclasp 124 rotationally constrained by the inner circumferential wall 102so that the clasp 124 is prevented from decoupling from at least one ofthe UAV and sabot clasp tabs (122, 126). In FIG. 4, the aperture 106 isillustrated having a constant cross section. In an alternativeembodiment, the aperture may have an expanding cross section in gradualpreparation for rotational release of the clasp 124 from the UAV clasptab 122, the sabot clasp tab 126, or both.

FIG. 5 depicts one embodiment of a launch tube 500 having a constantcross-sectional area along its length, with the sabot 510 detachablycoupled to the UAV 512 using a clasp 514 detachably connected to boththe sabot 510 and UAV 512 and rotationally constrained by the innercircumferential wall 516 of the launch tube 500. In this embodiment, thelaunch tube 500 is shown having an optional frangible seal 502 across atop opening of the launch tube 500. Two gas-generating canisters (504,506) are shown disposed within a high-pressure volume 508 of the launchtube 500. In FIG. 5, the adhesive coupling that previously restrainedthe sabot 510 in the launch tube 500 has been broken (See FIG. 3), andthe sabot 510 has moved a distance axially up the launch tube inresponse to a pressure differential between the high-pressure volume 508and the side of the sabot opposite from the high-pressure volume. TheUAV 512 is shown breaking the frangible seal 502 and beginning to exitthe launcher 500 as the clasp 514 continues to be rotationallyconstrained by the inner circumferential wall 516 to maintain thedetachable coupling between the sabot 510 and UAV 512.

FIG. 6 depicts the UAV launch tube of FIG. 5, with the gas-generatingcanisters (504, 506) increasing the pressure—as depicted by the gas600—within the high-pressure volume 508 between the innercircumferential wall 516 of the launch tube 500 and the sabot 510. Atether 604 may be attached to the inner circumferential wall 516 and/orto an inner base wall 606 via a tether reel or winding element 608.Relative to FIG. 5, the sabot 510 is shown displaced along the launchtube 500—in this example a right parallelepiped volume—moving with theUAV 512, which is detachably coupled to the sabot 510 by the clasp 514.In one embodiment, generation of gas by the gas generators (504, 506)may be staggered, so that one gas generator starts later in time thanthe other, to increase or sustain the pressure as the UAV 512 travelsalong and exits the launch tube 500.

FIG. 7 depicts the launch tube of FIGS. 5 and 6 as the sabot 510approaches full payout, or a maximum distance of travel, as limited bythe tether 604, to prevent the sabot 510 from exiting the launch tubeand to substantially retain the gas within the launcher volume forsubsequent controlled gas seepage into the surrounding atmosphere. Insome embodiments using hot or warm gas generators, the sabot 510 travelsapproximately no further than the location depicted in FIG. 7. As theclasp 514 slides past the inner circumferential wall 516, the clasp 514decouples from the UAV clasp tab 700 to allow the UAV 512 to continueunhindered out of the launch tube. In some embodiments, the maximumtravel of the sabot 510 may be extended to allow the clasp 514 todecouple from both the UAV clasp tab 700 and sabot clasp tab 702, suchas by allowing the clasp 514 to entirely clear the inner circumferentialwall 516. In such an embodiment, the sabot 510, or the expandable sabotskirt 704 portion of the sabot 510, may substantially retain the gaswithin the launcher volume for subsequent controlled gas seepage intothe surrounding atmosphere. The sabot 510 may also be provided with aside depression (not shown) to facilitate controlled release of the gaspast the sabot 510 at the full payout position, whether fully-clearingthe clasp 514 or not.

FIG. 8 depicts one embodiment of a launch tube 800 having anenlarged-aperture launch end. The clasp 514 is rotationally constrainedby the inner circumferential wall 820 of the launch tube 800 along aportion of the launch tube length, rather than along the entire lengthas illustrated in FIGS. 5 and 6. Two gas-generating canisters (802, 804)are shown disposed within a high-pressure volume 806 of the launch tube800. A tethered sabot 808 is shown disposed between the gas generatingcanisters (802, 804) and the UAV 810. The launch tube has ahigh-pressure aperture portion of constant cross-sectional area 812 toprovide enhanced launch velocity and an enlarged-aperture launch portion814 to accommodate a UAV payload 816 that may extend beyond theconventional fuselage of the UAV 810. For example, the UAV payload 816may provide for cameras, sensors or other devices that extend beyond thefuselage of the UAV 810. The UAV 810 is shown breaking an optionalfrangible seal 818 and beginning to exit the launcher 800 as the clasp514 continues to be rotationally constrained by an inner circumferentialwall 820 to maintain the detachable coupling between the sabot 808 andUAV 810.

FIG. 9 depicts the enlarged-aperture launch portion 814 and UAV launchtube 800 of FIG. 8, with the gas-generating canisters (802, 804)increasing the pressure—as depicted by the gas 900—within thehigh-pressure volume 806 between the sabot 808 and the gas-generatingcanisters (802, 804). A tether 902 may be attached to the innercircumferential wall 820 and/or to an inner base wall 904 via a tetherreel or winding element 906. Relative to FIG. 8, the sabot 808 is showndisplaced along the launch tube 800—in this example a rightparallelepiped volume—moving with the UAV 810, which may be detachablycoupled to the sabot 808 by the clasp 514. In the illustrated embodimentof FIGS. 8 and 9, the sabot 808 has not yet approached theenlarged-aperture launch portion 814 and so the clasp 514 is stilldepicted as rotationally restrained by the inner circumferential wall820 to detachably couple the UAV 810 to the sabot 808.

FIG. 10 depicts the clasp 514 illustrated in FIGS. 8 and 9 falling awayfrom the UAV 810 to decouple the UAV 810 from the sabot 808 in theenlarged-aperture launch portion 814 of the launch tube. As the clasp514 slides past the high-pressure aperture portion of constantcross-sectional area 812, the clasp 514 may no longer be rotationallyconstrained by the inner circumferential wall 820 and so the clasp 514may fall away from the UAV clasp tab 1000 to allow the UAV 810 tocontinue unhindered out of the launch tube. In some embodiments, thesabot 808 has an expandable sabot skirt 1002 that may be configured tosubstantially retain the gas within the launcher volume to providecontinued thrust of the sabot 808 substantially through theenlarged-aperture launch portion 814.

FIGS. 11 and 12 depict one embodiment of a launch tube 1100 having anenlarged-aperture launch portion 1104. The launch tube 1100 has ahigh-pressure aperture portion of constant cross-sectional area 1102 toprovide enhanced launch velocity, and an enlarged-aperture launchportion 1104 to accommodate a UAV payload 1106 that may extend beyondthe fuselage of the UAV 1108. Unlike the launch tube illustrated inFIGS. 8 and 9, the high-pressure aperture portion of constantcross-sectional area 1102 extends substantially throughout the launchtube 1100 length. In the embodiment illustrated in FIGS. 11 and 12, theenlarged-aperture launch end 1104 is introduced abruptly along thelaunch tube length to maximize the available high-pressure apertureportion length while accommodating the UAV payload 1106 toward the frontof the UAV 1108. A clasp 1110 detachably couples the UAV 1108 to a sabot1112 and is rotationally constrained by an inner circumferential wall1114 of the launch tube 1100 along a substantial portion of the launchtube length prior to reaching the enlarged-aperture portion 1104 so thatthe clasp 1110 does not rotate away from the UAV 1108 and sabot 1112. Asthe clasp 1110 slides past the inner circumferential wall 1114 of thehigh-pressure aperture portion 1102, the clasp 1110 is no longerrotationally constrained by the inner circumferential sidewall 1114 andso the clasp 1110 may fall away from the UAV 1108 to allow the UAV 1108to continue unhindered out of the launch tube 1100.

FIG. 13 depicts, in a bottom-side perspective view, an exemplary UAV ina pre-launch state 1300, i.e., with its wing 1302 and tail surfaces 1304folded beneath the fuselage of the vehicle. Also shown is a propellerhub 1306 about which a propeller may be rotatably mounted. The airvehicle may include a radio frequency (RF) antenna 1308 conformal withor extending from the vehicle. Whether the tube volume is a rightcylinder, a right parallelepiped, or some other shape, the cross-sectionor cross-sections of the UAV may be insufficient to maintain anair-tight fit between the vehicle and the inner walls of the launcher.Accordingly, for launches based on gas pressure, a sabot may be disposedbetween the gas source and the UAV.

FIG. 14 depicts an exemplary UAV in a launched state 1400 with itsairfoils 1302, 1304 deployed and its pusher propeller 1402 rotating. TheUAV may receive and/or send signals through an antenna, for example, anRF antenna 1308, which may be conformal with or extending out from thelaunched UAV 1400.

It is contemplated that various combinations and/or sub-combinations ofthe specific features and aspects of the above embodiments may be madeand still fall within the scope of the invention. Accordingly, it shouldbe understood that various features and aspects of the disclosedembodiments may be combined with or substituted for one another in orderto form varying modes of the disclosed invention. Further it is intendedthat the scope of the present invention herein disclosed by way ofexamples should not be limited by the particular disclosed embodimentsdescribed above.

What is claimed is:
 1. A system comprising: an unmanned aerial vehicle(UAV) launch tube; a sabot disposed in an interior of said UAV launchtube, said sabot comprising a first clasp tab and an expandable skirt,wherein said sabot is hollow, wherein said expandable skirt isconfigured to provide a pressure seal with an inner circumferential wallof said UAV launch tube, wherein said expandable skirt is disposedproximate an open end of the sabot, wherein said expandable skirt isdisposed distal from said first clasp tab, and wherein said expandableskirt further comprises a circumferential skirt protrusion extendingtoward said inner circumferential wall of said UAV launch tube; and aclasp detachably coupled to said first clasp tab and contacting saidinner circumferential wall of said UAV launch tube; wherein said claspis constrained by said inner circumferential wall and said first clasptab.
 2. The system of claim 1, wherein said expandable skirt isrestrained within said UAV launch tube by an adhesive.
 3. The system ofclaim 2, wherein said adhesive detachably binds said expandable skirtabout an exterior surface of a gas generator within said UAV launchtube.
 4. The system of claim 3, wherein said gas generator is configuredto generate gas between said expandable skirt and said exterior surfaceof said gas generator; and wherein the generated pressure of saidgenerated gas is sufficient to push said expandable skirt off of saidexterior surface of said gas generator by breaking said adhesiverestraint between the exterior surface of said gas generator and saidexpandable skirt.
 5. The system of claim 1, further comprising a UAVseated on said sabot, said UAV having a second clasp tab detachablycoupled to said clasp, and wherein said clasp is constrained by saidinner circumferential wall, said first clasp tab, and said second clasptab.
 6. The system of claim 1, wherein said sabot is tethered to saidUAV launch tube.
 7. The system of claim 1, wherein said expandable skirtis restrained within said UAV launch tube by a detachable binding. 8.The system of claim 7, wherein said detachable binding is configured tobind said expandable skirt about an exterior surface of a gas generatorwithin said UAV launch tube so that a generation of gas by a gasgenerator inside said gas generator pushes said expandable skirt off ofsaid exterior surface of said gas generator by breaking said detachablebinding.
 9. The system of claim 7, further comprising a UAV seated onsaid sabot, said UAV having a second clasp tab detachably coupled tosaid clasp; wherein said inner circumferential wall prevents said claspfrom slipping off of said second clasp tab while said UAV is in said UAVlaunch tube.
 10. The system of claim 1 further comprising: a gasgenerator disposed in the interior of said UAV launch tube; wherein saidexpandable skirt is detachably coupled to an exterior surface of saidgas generator via an adhesive coupling.
 11. The system of claim 10wherein said adhesive coupling is configured to break from resultant gaspressure from said gas generator creating a seal between said sabot andsaid inner circumferential wall of said UAV launch tube.
 12. The systemof claim 1 further comprising: a UAV and a second clasp tab of said UAV,wherein said UAV is detachably coupled to said sabot via said clasp, andwherein said clasp is detachably coupled to said first clasp tab andsaid second clasp tab.
 13. The system of claim 12, wherein said clasp isconfigured to decouple from said second clasp tab as said UAV exits saidUAV launch tube.
 14. The system of claim 12, wherein said clasp isconfigured to decouple from said first clasp tab and said second clasptab as said UAV exits said UAV launch tube.